Seminars relevant to Informatics

[Ohad Kammar <ohad.kammar AT ed.ac.uk>]

Hi,

Reminding that this week's LFCS seminar will start shortly:

  Tuesday, 22 Sep, 4.10pm

  Sabine Oechsner, Vrije Universiteit Amsterdam

  The seminar will take place in-person only.

  Sabine is visiting us for the week. If you'd like to meet with her, please reach out

  directly, or coordinate with Sam Lindley.

We're synchronising the seminar time with the teaching timetable, and

plan to start the talk at the advertised time, so please arrive a minute or two

earlier.

In detail:

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Sabine Oechsner, Vrije Universiteit Amsterdam

https://soechsner.de

  Tue, 22 Sep, 4.10pm

  Venue: Dugald Stewart Building DSB-1.20 (note unusual venue)

Title: Secure Computation in the Wild: When Cryptographic Protocols Meet the Real World

Abstract

Secure multiparty computation (MPC) allows mutually distrusting

parties to jointly compute a public function of their private inputs,

while hiding the inputs from each other. MPC protocols have been an

object of study since the 1980s, and recent years have seen interest in

deployment. However, protocol implementations frequently deviate

from the original protocol design, for example for performance

reasons or because of lack of specifications. While a formal security

analysis is the standard for any new MPC protocol design, it is

currently unclear how these security guarantees exactly translate

into implementations.

In this talk I will discuss concurrency as new source of gaps between

theory and practice of MPC security, and what we can learn about

analyzing the security of practical MPC protocols. Specifically, I

will be focusing on the SPDZ family of MPC protocols (Damgård et al.,

CRYPTO 2012, ESORICS 2013), which provides security against

malicious adversaries when all-but-one of the participants may be

corrupted. In a recent work, we identified a novel type of MAC key

leakage in the MAC check protocol of SPDZ, which can be exploited in

concurrent, multi-threaded settings, compromising output

integrity and, in some cases, input privacy. In our analysis of three

SPDZ implementations (MP-SPDZ, SCALE-MAMBA, and FRESCO), two are

vulnerable to this attack, while we also uncover further issues and

vulnerabilities with all three implementations. I will conclude by

discussing mitigation strategies as well as recommendations for

researchers, developers and users of MPC protocols.

Based on joint work with Alexander Kyster, Frederik Huss Nielsen, and

Peter Scholl (IEEE S&P 2025).

Link: https://ieeexplore.ieee.org/document/11023414

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If you would like to propose a speaker, or speak yourself, please contact me.

The seminar webpages:

http://web.inf.ed.ac.uk/lfcs/events/lfcs-seminars

Yours,

Ohad.

The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336. Is e buidheann carthannais a th’ ann an Oilthigh Dhùn Èideann, clàraichte an Alba, àireamh clàraidh SC005336.